1. Field of the Invention
The present invention relates to an external fixator for use in orthopedic surgical applications, and more particularly to a method and apparatus for external fixation of an elbow.
2. Discussion of the Related Art In various orthopedic surgical procedures, it is necessary to secure two bone portions in a relatively fixed relationship to each other. For example, the need for establishing such a secured relationship is often a result of a fracture which has occurred to the bone. To ensure that the bone can regenerate in the proper orientation and fuse the fracture, it is important that the bone portions be fixed and in the desired position during bone regeneration.
Various external fixation devices for the repair of traumatized bone are known. For example, U.S. Pat. No. 5,662,650 to Bailey et al. discloses an apparatus for the external fixation of large bones. The apparatus is illustrated to include a main body as well as a first and second bone screw clamps. The main body serves to allow the apparatus to axially rotate, thereby providing a proper longitudinal rotational location of the bone screws with respect to a bone. The first bone screw clamp is used to secure a first bone screw to the apparatus while permitting the first bone screw to be axially displaced from the main body. In a similar fashion, the second bone screw clamp functions to secure a second bone screw to the apparatus and to allow the second bone screw to be axially displaced with respect to the main body. U.S. Pat. No. 5,662,650 is incorporated by reference as if fully set forth herein.
In certain orthopedic surgical procedures, it is necessary to employ an external fixation device for immobilizing or restricting motion of a hinged joint such as the elbow joint. Many known devices for externally fixating an elbow joint require the insertion of an axis pin through the anatomical pivot axis. Another known device for elbow fixation is disclosed in U.S. Pat. No. 5,100,403 to Hotchkiss et al. which is entitled "Dynamic Elbow Support." The dynamic elbow support has proximal and distal support sections, means for rigidly connecting each support section to bone, and a pair of hinges connecting the support sections and pivoting at the joint. The pair of hinges permits movement of the support sections and their corresponding attached bone throughout flexion and extension. The hinge may be driven by a gear mechanism which may be disengaged by a clutch. The dynamic elbow support may also include a distraction mechanism for movement of the bones out of contact in the joint, while allowing for an active range of motion at the joint.
While known external fixators specifically designed for supporting an elbow joint may have proven to be acceptable for certain applications, such fixators are nevertheless susceptible to improvements that may enhance their performance.